Tag Archives: WithMockUser

A common requirement for secured applications is that admin / super users are able to login as any other user. For example, it may be helpful for a customer support analyst to access a system as if they were a real specific customer. The obvious way to do this is for the admin user to ask for the customer’s password or look it up in the password database. This is usually an unacceptable security compromise – no one should know a customer’s password except for the customer. And if the password database is implemented correctly it should be technically impossible for anyone – not even a system admin or DBA – to discover a user’s password.

An alternative solution is to allow admin users to login with their own unique username and password but allow them to then impersonate any other user. After the admin user has logged in, they can enter the username of another user and then view the application as if they were logged in as that user. Implementing user impersonation in this way also has the advantage that the system knows who has really logged in. If the system has an audit log, we can audit actions against the real admin user, rather than the impersonated user.

A common unit test scenario for Spring / Spring MVC applications is to verify behavior when logged in as a particular user. The new spring-security-test library available with Spring Security version 4 makes testing user access controls in Spring and Spring MVC applications far simpler.